Sounds like you are in the right place then. (And feel free to explore prescriptive things too; I don't mean to be discouraging either way at all.)
"Linguistics" (and some of the topics you mention) can refer to so many diverse topics it's hard to even know where to start. More specific recommendations can be made for more specific questions once you figure that out.
Curzan's book is a good one if you're not sure and also want to know about prescriptivism, and it may lead to other topics too. You could also start with something more formal, like a textbook, but that's probably not as much fun.
(Without sounding too judgmental, I will say that your observations seem right: anyone who takes language(s) seriously enough to get into Linguistics eventually comes around, at least in some ways, to the descriptive perspective. At least some of the interest in perspective grammar is somewhat superficial: telling people they should speak or write like you do, because you assume that's correct. There are some valid aspects of prescriptivism, for some purposes. But when you start looking more broadly, especially comparing languages, things look different. Familiarity supports interest and acceptance.)